Disturbance to outdoor insulators is caused by several factors and is generally caused by external factors, namely environmental factors. These environmental factors greatly affect the performance of insulators. To improve the performance of insulators, several attempts have been made, such as the use of new materials or surface coatings to increase the dielectric strength. Systematic efforts to improve insulator performance require an understanding of insulator behavior. Most of outdoor insulator failures occur on the surface. Therefore, efforts to improve the performance of outdoor insulators are focused on improving the insulator surface by applying surface treatments or coatings. In this paper, we review research papers that discuss insulator coating materials which results is better performance compared to the uncoated insulator. In this paper, we also propose local material for insulator coating, gum rosin, which is a residue from the distillation of pine tree sap. This product has characteristics namely hydrophobicity, adhesive promoter and viscosity so that it can be used as insulator coating. The final results of this study are expected to contribute to the improvement of insulator performance through insulator coatings. Finally, this insulator coating model can answer the needs of insulators in reduce in a failure problem of outdoor ceramic insulators and experiments were carried out using specimens that had been coated with gum rosin, the result was that the leakage current was reduced.